Add missing ShaderLoader*

src/osgEarth/ShaderLoader

@@ -0,0 +1,108 @@
+/* -*-c++-*- */
+/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
+ * Copyright 2008-2014 Pelican Mapping
+ * http://osgearth.org
+ *
+ * osgEarth is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+#ifndef OSGEARTH_SHADER_LOADER_H
+#define OSGEARTH_SHADER_LOADER_H 1
+
+#include <osgEarth/Common>
+#include <osgDB/Options>
+#include <map>
+
+namespace osgEarth
+{
+    class VirtualProgram;
+
+    /**
+     * Functions to help load shader code.
+     */
+    class OSGEARTH_EXPORT ShaderPackage
+    {
+    public:
+        /**
+         * Adds a function from this package to the VirtualProgram.
+         */
+        bool loadFunction(
+            VirtualProgram*       vp,
+            const std::string&    filename,
+            const osgDB::Options* dbOptions =0L ) const;
+
+        /**
+         * Removes a function loaded by loadFunction from the VirtualProgram.
+         */
+        bool unloadFunction(
+            VirtualProgram*       vp,
+            const std::string&    filename,
+            const osgDB::Options* dbOptions =0L ) const;
+
+    public:
+        typedef std::map<std::string, std::string> SourceMap;
+        const SourceMap& context() const { return _sources; }
+
+    protected:        
+        SourceMap _sources;
+    };
+
+    /**
+     * Base class for local shader file/source pairs.
+     */
+    class OSGEARTH_EXPORT ShaderLoader
+    {
+    public:
+        /**
+         * Loads shader source from the specified filename, and calls 
+         * setFunction() on the virtual program to install the shader.
+         * The shader much include #pragma definitions for both its
+         * entry point and its location, e.g.:
+         *
+         *   #pragma vp_entryPoint "oe_my_shader"
+         *   #pargma vp_location   "VERTEX_VIEW"
+         */
+        static bool loadFunction(
+            VirtualProgram*       vp,
+            const std::string&    filename,
+            const ShaderPackage&  package,
+            const osgDB::Options* dbOptions =0L );
+
+        /**
+         * Removes a function loaded by loadFunction from the VirtualProgram.
+         */
+        static bool unloadFunction(
+            VirtualProgram*       vp,
+            const std::string&    filename,
+            const ShaderPackage&  package,
+            const osgDB::Options* dbOptions =0L );
+
+        /**
+         * Loads shader source from the specified filename. If the
+         * file can't be found in the OSG file path, use the source
+         * provided in backupSource.
+         */
+        static std::string load(
+            const std::string&    filename,
+            const std::string&    backupSource,
+            const osgDB::Options* dbOptions =0L );
+
+        static std::string load(
+            const std::string&    filename,
+            const ShaderPackage&  package,
+            const osgDB::Options* dbOptions =0L );
+    };
+
+} // namespace osgEarth
+
+#endif // OSGEARTH_SHADER_LOADER